Data storage (e.g. whether pre-existing data needs to be migrated or processed in
a particular way to ensure consistency).

Data retrieval (e.g. whether existing queries are likely to need revising to take
account of the changes).

Communications (e.g. whether communication specification are likely to be affected
and in particular potential issues from cross-version communications).

Following discussion of these general considerations, the remainder of this section
holds specific advice related to any content changes in a release which are expected
to require attention from implementers.